Fatty matter refining process



June 27', 1939.. w. J. HUND ET AL FATTY MATTER REFINING PROCESS FiledJuly 17, 1957 Patented June 27, 1939 UNITED STATES PATENT OFFICE PATTYMATTER REFINTNG PRocEss Delaware Application July 17, 1937, Serial No.154,321

16 Claims.

This invention relates to a process for removing undesirableconstituents such as free fatty acids, certain coloring bodies,mucilaginous material, etc., from fatty matters, and has for its objectthe provision of a method affording a superior product, a moreeconomical execution and a minimum of loss, and at the same time amethod of such flexibility that it may be adapted to the refining of themost diverse crude fatty matters and products.

According to the present invention, the fatty matter to be refined isextracted with a suitable, substantially immiscible extractant andsubsequently washed .free of traces of the extractant, said extractionand washing operations being performed in a continuous multi-stagecounter current manner.

The accompanying drawing illustrates diagrammatically one suitable iowarrangement for a plant wherein the crude fatty matter may be subjectedto a two-stage extraction with a refining agent, followed by a two-stagewashing, both operations being performer in a continuous countercurrentmanner. It is to be understood that this arrangement may be alteredconsiderably without departing from the spirit of the invention. Thus,for example, one of the washing stages may be omitted; either theextraction or the washing or both may be performed in more 30 than twostages; treatment with a third or fourth agent may be inserted in one orin multiple stage; the capacity of the plant may be increased by usingseveral units in parallel, as, for example, `four mixer units, threeheating units, etc.

Referring to the drawing, the numerals I, 2 and 3 represent storagetanks for the crude fatty matter, extractant and wash water,respectively. The fatty matter storage tank I is preferably equippedwith heating means, such as, for instance, a steam coil. Numerals 4, 5and 6 represent pumps by means of which the above materials are suppliedto the system. Said pumps are preferably of such construction as toallow adjustment to a wide range of flow. Numerals l, 8, 9 and I0represent mixing devices, and numerals II, I2, I3 and I4 representseparating means, in this case centrifugal separators. Numerals I5, I6,I 'I and I8 represent pumps and numerals I9, 20, 2| and 22 representheating means, such as, for instance, steam heated coils.

Again referring to the drawing, the crude fatty matter as a liquid atthe desired temperature is `fed from tank I by pump 4 into mixer 'lwherein `it is thoroughly contacted with, but not emulsifed with, theonceusedextractant from separator I2.

(Cl. ZEW-425) The mixture is continually delivered by means of pump I5from mixer I to separator l I wherein the two phases are quicklyseparated. By means of a heating means I9, the temperature of themixture is adjusted to give efficient separation. The partially renedfatty matter leaving separator II ows to a mixer 8 wherein it isthoroughly contacted with fresh extractant fed continually to the mixerby pump 5 from tank 2. The mixture is delivered by means of pump Iii toseparator l2 wherein the phases are again quickly separated. A secondheating means 20 may be used to control the temperature and thus aidrapid separation. 'Ihe twice treated fatty matter from separator I2 thenflows to a mixer 9 wherein it is washed with once used water fromseparator I4. The mixture is then delivered by means of pump Il' toseparator I3 wherein the phases are quickly separated. The refined andpartly washed fatty matter from separator I3 iiows to mixer I wherein itis thoroughly contacted with fresh Water supplied continually from tank3 by pump 6. The mixture is delivered by means of pump I8 from mixer Ito separator Ill wherein the phases are quickly separated. The heatingmeans 2l and 22 allow temperature control during these later steps. Thefatty matter issues from separator I4 via pipe 25 in a well refined andsubstantially dry state.

During the course of refining the extractant and the wash agent flowcontinually in a countercurrent manner with respect to the fatty matter,i. e., from right to left. Thus the fresh extractant is fed continuallyby means of pump 5 into mixer 3 wherein it meets the partially refinedfatty matter from separator II. After being .thoroughly contacted inmixer 8 and the phases separated in separator I2, the once usedextractant flows to mixer I wherein it is thoroughly contacted with thecrude fatty matter continually ,40

fed from tank I by pump 4. The twice used extractant then issues fromseparator il through pipe 23.

The wash water travels a countercurrent path similar to that of theextractant being fed continually from tank 3 by pump 6, passingconsecutively through IU, I8, 22,14, 9, I'I, 2l, I3 and issuing Via pipe24.

We have found that the present method of refining is superior to theother known methods, especially as regards quality of product, lossesincurred during refining, adaptability'to the relining of various fattymattersas also the preservation of Valuable vitamine formingconstituents, amount of Vextractant `required and throughput capacity.The various advantages realizable through the use of our invention arebest appreciated in the light of the problems encountered in the art offatty matter refining.

The refining agents generally used in fatty `matter refining, such as,for example, aqueous alkalis, alkylolamines, dilute mineral acids, etc.,besides functioning as refining agents, all react with the fatty matterto a greater or less extent to effect a certain amount saponication,etc., of the fatty matter, which, in many cases, represents anappreciable loss. The loss resulting from this cause is by no meansrestricted to the actual amount of fatty matter reacted, but isconsiderably greater. Since the products of saponification, etc., areusually active emulsifying agents, they considerably lengthen the timerequired for phase separation, thereby causing longer time of contactwith the result of further reaction, and by preventing a sharpinterface, cause the loss of unsaponified oil by removal with theemulsified layer.

Since the refining agents function to a large extent as trueextractants, the degree of refining and the percentage losses are, otherthings being equal, dependent upon the effective time of contact, and,being so, are dependent one upon the other. In such cases, therefore,where a highly refined product is desired, the refiner is usuallyconfronted with a substantial loss, and this loss frequently determinesthe degree of refining economically practical.

We have found that the present continuous multi-stage countercurrentmethod is superior to other methods in this respect, since, other thingsbeing equal, the present method produces a more highly refined product.

Notwithstanding the fact that in executing the present invention, thefatty matter is actually subjected two or more times to the action f therefining agent, we have found that, other things being equal, thepresent method incurs less loss than the known methods. This is adecided advantage, especially when treating costly materials, such as,for example, the refining of cod liver oil or carrot oil. This advantageis achieved by several features inherent in the continuous multi-stagecountercurrent process.

Although a certain amount of loss duetoreaction is incurred during themixing operation and is unavoidable, a substantial proportion of suchloss occurs during the separation of the phases, during transfer, inwaiting tanks, etc. Thus, fatty matters, after being treated with arefining agent and separated therefrom, always contain small quantitiesof the refining agent which may react with the fatty matter at anappreciable rate. In order to reduce the losses to a practical minimum,the present method is so adapted as to afford the least contact betweenthe reactants except that required during the mixing operation.

Immediately upon issuing from the mixing operation, the phases areseparated, as, for instance, in a centrifugal separator, and theseparated phases are immediately subjected to the next following step,etc., until the product has been completely treated.

Thus, the fatty matter from the first refining stage is piped directlyto the second mixer (mixer 8). The product from the last stage ofrefining is subjected immediately and continually to a washingtreatment, followed by a separation of the phases. We prefer to subjectthe raffinate to a continuous two-stage washing treatment, although thissecond stage is not usually necessary.

The once washed raffinate contains only minute quantities of refiningagent, and therefore, does not necessitate further promptness inhandling. The once washed raffinate may be batch washed, stored,filtered, bleached, dried or otherwise treated as the case may require.

Since it is desirable to eliminate all unnecesn sary contact of therefining agent and the fatty matter, and since the time required forphase separation represents such undesirable contact, it is advantageousto execute the phase separation promptly and as efficiently aspractically feasible. We have found that centrifugal separator machinesare eminently suited for such separation. If the fatty matter inquestion contains appreciable quantities of sludge forming materials, acentrifugal separator provided with a sludge type bowl may beadvantageously used for the first separator, (separator Il). However,any means whatsoever which will effect a prompt separation may be used.In some cases where the fatty matter responds to treatment with a verydilute or weak agent, such as a 1% solution of NaOH, ordinary gravityseparation may be applicable.

The present method has the further advantage, other things being equal,of requiring less refining agent. This advantage can in some casesresult in a substantial lowering of the refining costs.

Another advantage of the present method is its flexibility, i. e., itsadaptability to the refining of the most varied fatty matters with theusual refining agents. According to the quality of the crude fattymatter and the ultimate use to which the refined product is to beemployed, a wide variety of problems are encountered in the refining offatty matters. Thus for example, oils that have been stored for sometime behave differently than fresh oils, and, therefore, sometimesrequire radical changes in the refining process. Likewise, cold pressedoils are usually much more difficult to refine than hot-pressed oils.Oils obtained from old or bruised seed contain certain other impuritieswhich require special methods for their removal. All oils are known tovary with the season of harvesting and the locality of production.Certain oils often contain impurities which act as emulsifying agents,and such oils usually require a substantial departure from the usualrefining methods. Such variations as are required for each individualcase, such as giving a preliminary treatment with water, dilute alkali,dilute acid, or variation of the strength, kind or amount of refiningagent, alteration of the temperature, or time of mixing, etc., areeasily accommodated by the present method. Any of the usual refiningagents, such as various strengths of HCl, H2SO4, H3PO4, KOH, NaOH,Na2CO3, NaHCO3, NasPOi, alkylolamine, dialkylolamine, etc., may beemployed in the present invention. In the usual refining practice theseagents function both as reactants and as extractants, and in such casesthey are used in considerable excess. In a few cases, such as when it ismerely desired to remove the fatty acids, the refining agent may be usedin approximately the stoichiometric amount. When desirable, as whenusing an alkylolamine as a refining agent, the used agent may berecovered by any of the known methods and reused.

The use to which an oil is to be employed requires further variation inthe refining methods. Thus, for example, a sardine oil destined forpoultry feed must be refined without serious loss of vitamine, while ifthe same oil isvto be used as a paint oil, the preservation of thevitamins is of no consequence and the rening process must be executed soas to substantially remove all the coloring bodies, and at the same timeimprove the drying qualities of the oil. In the refining of edible oils,little attention has been given in the past to the preservation of suchvaluable components as` Carotin. .This substance, which is a valuablesource of vitamine, is exceedingly susceptible to oxidation, absorbingabout 34% of its Weight of oxygen to revert to a` colorless valuelessconstituent. According to the present method., the fatty mattersubjected to treatment is allowed little opportunity to oxidize. Sinceunder the preferred mode of operation themixer units 1, 8, 9 and l0 arecompletely filled with liquid, oxidation of the carotin during mixing issubstantially obviated.

The present invention is applicable to the refining of fatty matter ofanimal, vegetable or synthetic origin. Thus, for example, hot pressed,cold pressed and unclaried hot pressed California cottonseed oil, soyabean oil, palm oil, linseed oil, sardine oil, perilla oil, corn oil,peanutoil, cohune nut oil, and sundried and smoke dried copra oils havebeen successfully refined by the present method.

While, in order to efciently refine a given fatty mattei', it is quiteoften necessary to alter the rening method materially, such as by usingan entirely different refining agent, by using a plurality of refiningagents, by giving accessory treatments, etc., it often happens thatfatty matters differ mainly in the relative amounts of the impuritiespresent, and in such cases adjustment of the effective contact isusually sufficient to insure maximum efficiency of refining. Since theeffective contact is dependent upon the time of contact, degree orintimacy of contact, and strength and quantity of reagent, this valuemay be fixed by adjustment of any of said variables. An optional meansof altering the'time of mixing may be afforded through the use of asubdivided mixing unit. Instead of using one mixing device, the mixingin o-ne or more cases may be effected in a plurality of smaller mixingmeans, preferably connected in such a manner as to allow their use inseries or in parallel. With such an arrangement, it is possible to alterthe effective volume and thereby the effective time of mixing withoutchanging the throughput rate of the plant, as, for instance, by shuntingout one unit of the mixing battery. In some cases, where a single mixingdevice is used, it is possible to control the time of mixing throughvariation of the quantity of liquid therein. However, while this latermethod is applicable to the refining of varnish oils, etc., itnecessitates the providing of an oxygen free atmosphere above the liquidwhen the vitamine content of the fatty matter is of import.

The capacity of a satisfactory mixing device or the total capacity ofthe units, if subdivided, may vary considerably. We have found that acapacity equal to about one-seventh of the capacity of the plant perhour is one suitable size.

Since fatty matters vary considerably in their tendency to formemulsions, mechanical mixing devices, such as paddles, propellers, etc.,capable of variable speed are advantageously used. Through adjustment ofthe speed, the degree of mixing may thus be regulated to give themaximum effective contact for any particular fatty matter without undulyemulsifying the same. Other means of agitation, such as baffles,orifices,

etc., if properly constructed, should be applicable.

The present continuous, multi-stage, countercurrent process, since it isinherently more efiicient than any of the known processes, iseffectively executed with less violent contacting of the fatty matterand extractant and consequently allows a quicker and easier separationof the phases. This not only reduces the losses, but increases thethroughput capacity of the plant. Since the operations are rapid and notinterrupted by waiting tanks, etc., the present process affords a plantrequiring a relatively small space and having a high throughputcapacity. The compact nature, thus afforded, permits of ease ofcleaning, small loss of heat, and a minimum tendency for high meltingfats, etc., to freeze in the pipes.

As illustrative of the use, conditions and results of one embodiment ofour invention, we

offer the following:

Example I A particularly refractive cold pressed cottonseed oil havingan appreciable content of sludge forming material, when refined underoptimum conditions by the best of the known methods, produced an oilhaving a color of 35 yellow and 12.6 red (Lovibond Tintometer scale) Thecolor of this oil upon bleaching reduced to 20 yellow and 4.6 red. 804lbs. of this same oil, treated in a continuous two-stage countercurrentmanner, using the same amount and kind of reagent, namely, 3.1% byvolume of 24 B. caustic soda solution, yielded 768.5 lbs. of treatedproduct having a color of 35 yellow and 8.1 red. Upon bleaching, theproduct had a color of 20 yellow and 2.2 red.

In this experiment, the separations were achieved in centrifugalseparators running at about '7200 R. P. M. The rst separator was notequipped with a sludge type bowl and this necessitated running theseparation at a higher temperature than customary. The mixers consistedof two one-gallon mixing devices provided with motor driven submergedpaddles, and connected in series. The total time of residence was 40mindtes which was divided into 20 minutes for washing and 2O minutes forextracting, this latter being in turn subdivided into 16 minutes formixing and 4 minutes` for separating, heating and transportation fromone step to the next.

Upon consider-ation of the advantages offered by the present continuousmulti-stage, countercurrent method, it is seen that this method hasdistinct advantages not possessed by counter current tower extraction,single phase extraction,

batch methods, etc., and that it isnot equivalent to simply running aproduct through a refining plant two or more times. Thus, the presentproc'- ess offers economy of space and `adaptability to Depending uponthe most varied fatty matters. the feature most desired, the presentmethod can be used to advantage to produce a more highly refinedproduct, reduce the losses or effect a saving in the amount of refiningagent used.

It is to be noted that the advantages realizable through the use of thepresent invention spring from the continuous, multi-stagecounter-current manner in which the process is executed. While in thepreferred embodiment, the process is arranged and executed in such amanner as to be distinctly advantageous for the refining o-f the mostvaried fatty matters, itis to be remembered that for a particular caseit mayynot be necessary to utilize all the advantages simultaneously,and that for this reason considerable variation in the details of theexecution may some times be possible Without departing from the spiritof the invention.

We claim as our invention:

l. A process for the refining of fatty matters in a continuous,multi-stage countercurrent manner, which comprises contacting a fattymatter in the first stage With a substantially immiscible basic actingextractant in the liquid state which is reactive with said fatty matter,said extractant having been previously contacted With and separated fromthe partially refined fatty matter in the second stage, separating thebulk of the extractant from the fatty matter, contacting the onceextracted oleaginous phase in the second stage With a purer portion ofextractant, separating the bulk of the extract phase from the fattymatter, and contacting the extract phase from the second stage With thecrude fatty matter in the first stage.

2. A process for the refining of fatty matters in a continuous,multi-stage countercurrent manner, which comprises contacting a fattymatter in the first stage with a substantially immiscible basic actingextractant in the liquid state which is reactive With said fatty matter,said extractant having been previously contacted With and separated fromthe partially refined fatty matter in the second stage, heating themixture, separating the bulk of the extractant from the fatty matter,contacting the once extracted oleaginous phase in the second stage witha purer portion of extractant, heating the mixture, separating the bulkof the extract phase from the fatty matter and contacting the extractphase from the second stage with the crude fatty matter in the firststage.

3. A process for the refining of fatty matters in a continuous,multi-stage countercurrent manner, which comprises contacting a fattymatter in the first stage with a substantially immiscible basic actingextractant in the liquid state which is reactive With said fatty matter,said extractant having been previously contacted with and separated fromthe partially refined fatty matter in the second stage, promptlyseparating the bulk of the extractant from the fatty matter, promptlycontacting the once extracted oleaginous phase in the second stage witha purer portion of extractant, promptly separating the bulk of theextract phase from the fatty matter, and promptly contacting the extractphase from the second stage With the crude fatty matter in the firststage.

4. A process for the refining of fatty matters in a continuous,multi-stage countercurrent manner, which comprises contacting a fattymatter in the first stage with a substantially immiscible basic actingextractant in the liquid state which is reactive with said fatty matter,said extractant having been previously contacted with and separated fromthe partially refined fatty matter in the second stage, centrifugallyseparating the bulk of the extractant from the fatty matter, contactingthe once extracted oleaginous phase in the second stage with a purerportion of extractant, separating centrifugally the bulk of the extractphase from the fatty matter, and contacting the extract phase from thesecond stage with the crude fatty matter in the rst stage.

5. A process for the refining of fatty matters in a continuous,multi-stage countercurrent manner, which comprises contacting a fattymatter in the first stage with a substantially immiscible basic actingextractant in the liquid state which is reactive With said fatty matter,said extractant having been previously contacted with and separated fromthe partially refined fatty matter in the second stage, separating thebulk of the extractant from the fatty matter, contacting the onceextracted oleaginous phase in the second stage with a purer portion ofextractant, separating the bulk of the extract phase from the fattymatter, contacting the extract phase from the second stage with thecrude fatty matter in the first stage, and finally subjecting theextracted fatty matter from the last stage to a Washing treatment.

6. A process for the refining of fatty matters in a continuous,multi-stage countercurrent manner, which comprises contacting a fattymatter in the first stage with a substantially immiscible basic actingextractant in the liquid state which is reactive with said fatty matter,said extractant having been previously contacted with and separated fromthe partially refined fatty matter in the second stage, heating themixture, promptly separating the bulk of the extractant from the fattymatter, promptly contacting the once extracted oleaginous phase in thesecond stage with a purer portion of extractant, heating the mixture,promptly separating the bulk of the extract phase from the fatty matter,and promptly contacting the extract phase from the second stage with thecrude fatty matter in the first stage.

'7. A process for the refining of fatty matters in a continuous,multi-stage countercurrent manner, which comprises contacting a fattymatter in the first stage with a substantially immiscible basic actingextractant in the liquid state which is reactive with said fatty matter,said extractant having been previously contacted with and separated fromthe partially refined fatty matter in the second stage, heating themixture, centrifugally separating the bulk of the extractant from thefatty matter, contacting the once extracted oleaginous phase in thesecond stage with a purer portion of extractant, heating the mixture,separating centrifugally the bulk of the extract phase from the fattymatter, and contacting the extract phase from the second stage with thecrude fatty matter in the first stage.

8. A process for the refining of fatty matters in a continuous,multi-stage countercurrent manner, which comprises contacting a fattymatter in the first stage with a substantially immiscible basic actingextractant in the liquid state which is reactive with said fatty matter,said extractant having been previously contacted with and separated fromthe partially refined fatty matter in the second stage, heating themixture, separating the bulk of the extractant from the fatty matter,contacting the once extracted oleaginous phase in the second stage witha purer portion of extractant, heating the mixture, separating the bulkof the extract phase from the fatty matter, contacting the extract phasefrom the second stage with the crude fatty matter in the first stage,and finally subjecting the extracted fatty matter from the last stage toa washing treatment.

9. A process for the refining of fatty matters in a continuous,multi-stage countercurrent manner, which comprises contacting a fattymatter in the rst stage with a substantially immiscible basic actingextractant in the liquid state which is reactive with said fatty matter,said extractant having been previously contacted With and separated fromthe partially refined fatty matter in the second stage, promptlyseparating centrifugally the bulk of the extractant from the fattymatter, promptly contacting the once extracted oleaginous phase in thesecond stage with a purer portion of extractant, promptly separatingcentrifugally the bulk of the extract phase from the fatty matter, andpromptly contacting the extract phase from the second stage with thecrude fatty matter in the first stage.

10. A process for the refining of fatty matters in a continuous,multi-stage countercurrent manner, which comprises contacting a fattymatter in the first stage with a substantially immiscible basic actingextractant in the liquid state which is reactive with said fatty matter,said extractant having been previously contacted with and separated fromthe partially refined fatty matter in the second stage, promptlyseparating the bulk of the extractant from the fatty matter, promptlycontacting the once extracted oleaginous phase in the second stage witha purer portion of extractant, promptly separating the bulk of theextract phase from the fatty matter, promptly contacting the extractphase from the second stage with the crude fatty matter in the firststage, and finally subjecting the extracted fatty matter from the laststage promptly to a washing treatment.

1l. A process for the refining of fatty matters in a continuous,multi-stage countercurrent manner, which comprises contacting a fattymatter in the rst stage with a substantially immiscible basic actingextractant in the liquid state which is reactive with said fatty matter,said extractant having been previously contacted with and separated fromthe partially refined fatty matter in the second stage, separatingcentrifugally the bulk of the extractant from the fatty matter,contacting the once extracted oleaginous phase in the second stage witha purer portion of extractant, separating centrifugally the bulk of theextract phase from the fatty matter, contacting the eX- tract phase fromthe second stage with the crude fatty matter in the first stage, andfinally subjecting the extracted fatty matter from the last stage to aWashing treatment.

12. A process for the refining of fatty matters in a continuous,multi-stage countercurrent manner, Which comprises contacting a fattymatter in the rst stage With a substantially immiscible basic actingextractant in the liquid state Which is reactive With said fatty matter,said extractant having been previously contacted With and separated fromthe partially refined fatty manner in the second stage, heating themixture, promptly separating centrifugally the bulk of the extractantfrom the fatty matter, promptly contacting the once extracted oleaginousphase in the second stage With a purer portion of extractant, heatingthe mixture, promptly separating centrifugally the bulk of the extractphase from the fatty matter, and promptly contacting the extract phasefrom the second stage with the crude fatty matter in the first stage.

13. A process for the refining of fatty matters in a continuous,multi-stage countercurrent manner, which comprises contacting a fattymatter in the first stage with a substantially immiscible basic actingextractant in the liquid state Which is reactive With said fatty matter,said extractant having been previously contacted With and separated fromthe partially refined fatty matter in the second stage, heating themixture, promptly separating the bulk of the extractant from the fattymatter, promptly contacting the once extracted oleaginous phase in thesecond stage with a purer portion of extractant, heating the mixture,promptly separating the bulk of the extract phase from the fatty matter,promptly contacting the extract phase from the second stage with thecrude fatty matter in the iirst stage, and finally subjecting theextracted fatty matter from the last stage promptly to a Washingtreatment.

14. A process for the refining of fatty matters in a continuous,multi-stage countercurrent manner, which comprises contacting a fattymatter in the first stage With a substantially immiscible basic actingextractant in the liquid state which is reactive with said fatty matter,said extractant having been previously contacted with and separated fromthe partially refined fatty matter in the second stage, promptlyseparating centrifugally the bulk of the extractant from the fattymatter, promptly contacting the once extracted oleaginous phase in thesecond stage with a purer portion of extractant, promptly separatingcentrifugally the bulk of the extract phase from the fatty matter,promptly contacting the extract phase from the second stage with thecrude fatty matter in the first stage, and finally subjecting theextracted fatty matter from the last` stage,

promptly to a Washing treatment.

15. A process for the refining of fatty matters in a continuous,multi-stage countercurrent manner, which comprises contacting a fattymatter in the first stage With a substantially immiscible basic actingextractant in the liquid state which is reactive with said fatty matter,said extractant having been previously contacted with and separated fromthe partially refined fatty matter in the second stage, heating themixture, promptly separating centrifugally the bulk of the extractantfrom the fatty matter, promptly contacting the once extracted oleaginousphase in, the second stage With a purer portion of ex tractant, heatingthe mixture, promptly separating centrifugally the 'bulk of the extractphase from the fatty matter, promptly contacting the extract phase fromthe second stage With the crude fatty matter in the first stage, andfinally subjecting the extracted fatty matter from the last stagepromptly to a Washing treatment.

16. A process for the refining of fatty matters in a continuoustwo-stage countercurrent manner, which comprises contacting a fattymatter in the iirst stage with a substantially immiscible basic actingextractant in the liquid state Which is reactive with said fatty matter,said extractant having been previously contacted With and separated fromthe partially refined fatty matter in the second stage, heating themixture, promptly separating centrifugally the bulk of the extractantfrom the fatty matter, promptly contacting the once extracted oleaginousphase in the second stage with a purer portion of extractant, heatingthe mixture, promptly separating centrifugally the bulk of the extractphase from the fatty matter, promptly contacting the extract phase fromthe second stage with the crude fatty matter in the first stage, andfinally subjecting the extracted fatty matter from the last stagepromptly to a Washing treatment.

WALTER J. HUND. DONALD I-I. ROWE.

